Physics for the 21st Century, set of 11 videos about current frontiers of physics. Two of our Physics faculty appear in these videos, Professor Mark Kruse appears in Unit 1 (searching for the Higgs particle at the Fermilab Tevatron) and Professor Ayana Arce appears in Unit 2 (about the Large Hadron Collider).

Magnetic levitation of a living frog in a solenoid that generates a 16 tesla magnetic field. A nice discussion of the science behind the levitating frog is given here and involves the concept of diamagnetisma weak repulsion that any material object feels when pushed into a magnetic field.

Note: One tesla is about 10,000 times stronger than the Earth's magnetic field at sea level so a 16 T field is strong indeed. In fact, this field strength would quench a superconductor so one has to use a solenoid build out of "ordinary" metal to generate such a strong field. Can you figure out what it would take to float a 65 kg Duke student via diamagnetism?

Inner Life of a Cell. Although this simulation is perhaps more well known to biologists as an illustration of the extraordinary complexity of a living cell, it is full of interesting examples of equilibrium and nonequilibrium phenomena of interest to physics students. Examples shown in the video include: self-assembly of microtubules, kinesin motors that transport vesicles along microtubule railways, transcription of DNA followed by translation into proteins, diffusion of intramembrane proteins in a liquid lipid bilayer, and so on. Most of what is shown in this movie is poorly understood, there are many interesting open questions to explore.

Homemade Spacecraft:a video from a simple home-brewed device consisting of a thermally insulated video recorder attached to a weather balloon, with a cellphone included to indicate the GPS location of the device.

Feynman:

Feynman video lectures on the character of physical law. Richard Feynman was one of the great theoretical physicists of the 20th century and a great expositor of physics. In the 1960s, he gave several popular public lectures about physics at Cornell University that later turned into a book The Character of Physical Law. You may especially enjoy the sixth lecture about the quantum mechanical view of nature.

Fun To Imagine, some videos of Feynman explaining science to a television audience.

The current (2010-2011) television series Through the Wormhole, narrated by Morgan Freeman, has numerous physics-related themes that you will likely enjoy: time travel, black holes, and antimatter are several examples.

This related website discusses an actual related example that occurred when, in 1978, a graduate student accidently put his head in the path of a proton beam from the U-70 particle accelerator in Russia. This was the world's most powerful accelerator in 1967, with a maximum beam of energy of about one percent the energy of the LHC. Remarkably, the student survived the experience.

Duke's Society of Physics Students likes to hold a liquid nitrogen party once each semester for all interested students. Here are some videos of fun things you can do with liquid nitrogen:

Make a liquid nitrogen bomb by dropping a large plastic soda bottle filled with liquid nitrogen into a trash can filled with warm water. (Searching for "liquid nitrogen bomb" on YouTubewill lead to many similar videos.

The physics? This is the ideal gas law PV=NkT at work. At room temperature (T~300 K), the liquid nitrogen initially at about 70 K in the bottle warms up and turns into a lot of gas (the gas is about 600 times less dense than the liquid). The large amount of gas in a small volume V creates a large pressure P=NkT/V that exceeds the material strength of the plastic bottle and causes the explosion. (Can you figure out where the bottle breaks first as internal pressure increases?)

Magnetic levitationby a ceramic material (the black block sitting in liquid nitrogen) that becomes superconducting at liquid nitrogen temperatures. A strong magnet (the shiny cylinder) placed over the block starts to descend by gravity but before it can move an observable distance, its descent induces powerful eddy currents in the superconductor that create an opposing magnetic field that suspends the magnet in the air. Once the superconductor warms up (after all the liquid nitrogen evaporates away), the eddy current disappears and the magnet lowers itself gently to the ground.

Note: This magnetic levitation via a superconductor is similar to the levitation by diamagnetic repulsion of a frog mentioned above.

Cloud chamberthat reveals the passage of invisible high energy subatomic particles moving through the air. Many science museums have a big cloud chamber: a dark box with what looks like a fine mist falling, with white vapor trails that appear randomly when a rapidly moving charged particle like a muon or proton (cosmic ray) passes through the fog. (The particles could also come from some radioactive source placed in the chamber.) As a charged particle moves through the supersaturated alcohol vapor, it ionizes alcohol molecules which then triggers local condensation of the gas into a small liquid droplet, which then scatters light and is visible as a white spot. The group of spots along the trail is basically a small linear artificial cloud, hence the name "cloud chamber".

Cloud chambers are easy to build and great fun. You are welcome to set up and try the commercially made cloud chamber in the Physics Demo room.